From b27b34a76fa16fcb96632a5bf245f3876183c479 Mon Sep 17 00:00:00 2001 From: John Wiegley Date: Sun, 15 Apr 2007 12:55:22 +0000 Subject: Added a reference to gdtoa, for doing expected conversion of double to amount. --- gdtoa/strtodnrp.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 87 insertions(+) create mode 100644 gdtoa/strtodnrp.c (limited to 'gdtoa/strtodnrp.c') diff --git a/gdtoa/strtodnrp.c b/gdtoa/strtodnrp.c new file mode 100644 index 00000000..19a769f0 --- /dev/null +++ b/gdtoa/strtodnrp.c @@ -0,0 +1,87 @@ +/**************************************************************** + +The author of this software is David M. Gay. + +Copyright (C) 2004 by David M. Gay. +All Rights Reserved +Based on material in the rest of /netlib/fp/gdota.tar.gz, +which is copyright (C) 1998, 2000 by Lucent Technologies. + +Permission to use, copy, modify, and distribute this software and +its documentation for any purpose and without fee is hereby +granted, provided that the above copyright notice appear in all +copies and that both that the copyright notice and this +permission notice and warranty disclaimer appear in supporting +documentation, and that the name of Lucent or any of its entities +not be used in advertising or publicity pertaining to +distribution of the software without specific, written prior +permission. + +LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, +INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. +IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY +SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER +IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, +ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF +THIS SOFTWARE. + +****************************************************************/ + +/* This is a variant of strtod that works on Intel ia32 systems */ +/* with the default extended-precision arithmetic -- it does not */ +/* require setting the precision control to 53 bits. */ + +/* Please send bug reports to David M. Gay (dmg at acm dot org, + * with " at " changed at "@" and " dot " changed to "."). */ + +#include "gdtoaimp.h" + + double +#ifdef KR_headers +strtod(s, sp) CONST char *s; char **sp; +#else +strtod(CONST char *s, char **sp) +#endif +{ + static FPI fpi = { 53, 1-1023-53+1, 2046-1023-53+1, 1, SI }; + ULong bits[2]; + Long exp; + int k; + union { ULong L[2]; double d; } u; + + k = strtodg(s, sp, &fpi, &exp, bits); + switch(k & STRTOG_Retmask) { + case STRTOG_NoNumber: + case STRTOG_Zero: + u.L[0] = u.L[1] = 0; + break; + + case STRTOG_Normal: + u.L[_1] = bits[0]; + u.L[_0] = (bits[1] & ~0x100000) | ((exp + 0x3ff + 52) << 20); + break; + + case STRTOG_Denormal: + u.L[_1] = bits[0]; + u.L[_0] = bits[1]; + break; + + case STRTOG_Infinite: + u.L[_0] = 0x7ff00000; + u.L[_1] = 0; + break; + + case STRTOG_NaN: + u.L[0] = d_QNAN0; + u.L[1] = d_QNAN1; + break; + + case STRTOG_NaNbits: + u.L[_0] = 0x7ff00000 | bits[1]; + u.L[_1] = bits[0]; + } + if (k & STRTOG_Neg) + u.L[_0] |= 0x80000000L; + return u.d; + } -- cgit v1.2.3